I’m going to convert my computer chair from pneumatic to static. I’m currently using plastic clasps that are held on with jubilee clips, but they’re not great and need replaced (I’m a heavy lad). A sturdy metal version would be better.
I’m assuming the plumbing world would have something like this, but the language of the plumber is arcane and inaccessible to regular goombas like me. What do I type into the search box?
Cheers!
Clamshell clamps or Truss Clamps aren’t exactly what youre looking for, but they’ll work. Clamshell clamps are used in automotive and plumbing applications, truss clamps are used for mounting lights and speakers to stage trusses. You can get them cheap on amazon, and stacking several of them up works great for spacing shafts.
“Stroke Limiting Shaft Collars” are exactly what you’re looking for, since they’re designed to do exactly what you’re attempting here but for industrial pneumatic or hydraulic equipment. Unfortunately since they’re for industrial equipment, they can be stupid expensive and a royal PITA to find. But they do have a very silly name, even for hydrualic equipment (which is a field whose jargon is entirely made up of double entendre), which is a point in their favor. Also, many of them work very well as bearing surfaces!
PLEASE be careful messing with the cylinders in office chairs though. It doesnt sound like youre planning to, but just a blanket warning. Much like garage door springs, those cylinders store WAY more energy than you would believe, and fucking up trying to take apart a damaged cylinder can send the piston an impressive distance through your chest.
In fact, if you look at the bottom of your chair where it sits on top of the piston, there should be a solid metal plate just above that. That metal plate is specifically placed there to avoid any surprise butt-stuff from a piston failing and rocketing up through the seat cushion. Because if that plate isn’t there, you will end up with a piston lodged three inches into your ass/taint area.
Thank you so much, those shaft collars look to be a much better design than the thing I drew (not much of a surprise to be honest!), I can stack a series of these instead of looking for one big solid one.
I didn’t know that the cylinders were so dangerous 😬 I must have lucked out; I’ve had to use extreme brute-force methods to dislodge the old ones when it was time to replace them, pointing the thing directly at my guts and face while I work it loose with a hammer and spanner. Sounds like I was unwittingly playing Russian roulette with my chair. The difficulty I have in pulling out the cylinder is why I wanna just go with a “static” setup, it’s way too much work and effort for something so simple. Now I can also add “don’t want my cheekbones to get lodged in the ceiling” to the list of reasons to go static.
Thanks for the info and the warning!
No problem, I’m just glad all that time I spent memorizing the McMaster-Carr catalog finally came in handy!
The cylinders are sealed units, so they’re safe to handle even after beating the crap out of them. The danger happens when people decide to repair a failing seal or leak and try to open the cylinder itself to get at the piston head - usually with a hacksaw…